1. Field of the Invention
The present invention relates to a wireless communication system and, more particularly, to a method of sending, by a base station, downlink data for supporting narrow-band user equipment and an apparatus using the same.
2. Related Art
3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is an improved type of a Universal Mobile Telecommunication System (UMTS) and introduced as 3GPP release 8. 3GPP LTE uses Orthogonal Frequency Division Multiple Access (OFDMA) in downlink and uses Single Carrier-Frequency Division Multiple Access (SC-FDMA) in uplink. 3GPP LTE-advanced (LTE-A), that is, an evolved type of 3GPP LTE, is recently being discussed.
In the next systems of LTE-A, low-price/low-specification User Equipment (UE) based on data communication, such as meter reading, water-level measurement, the use of a surveillance camera, and the inventory reports of vending machines is taken into consideration. Such UE is called Machine Type Communication (MTC) UE. In MTC, the size of transmitted data is small, and the transmission and reception of data are sometimes generated. Accordingly, it is preferred that the price of a device be lowered and the consumption of a battery be reduced using such MTC characteristics.
In particular, in order to reduce the complexity of the Radio Frequency (RF) unit of MTC UE, an operating frequency bandwidth may be configured to be narrow. There is a need for a scheme for supporting MTC UE which operates in a relatively narrow band compared to existing UE.